This invention relates to a novel water-borne ink, its composition and its use as a surface printing ink for printing plastic substrates such as polyolefin, polyester, polyamide and paper substrates coated with plastic polymers of this type. In addition, the invention is directed to the preparation of novel polyamide resin compositions and their use as binder resin in surface printing inks.
Surface printing inks are liquid inks which dry by solvent evaporation sometimes with heat or air blower assistance.
Solvent systems may be either water systems which use water as a partial or total solvent, or systems using volatile organic solvents. Primary solvents are usually alcohols, though some contain other oxygenated and/or aliphatic solvents.
Commonly used film formers for printing unto plastic substrates are usually solvent based. Water based inks have found limited use and are typically made by raising the alkalinity (pH) of an ink system to solubilize carboxylic resins such as rosin resins, modified acrylics and other acidic film formers. Inks of this type have found limited applicability for printing onto plastic substrates.